Do Invasive Electrode Designs Predict Surgical Outcome in Patients With Intractable Epilepsy?

BACKGROUND: In light of discordant diagnostic results during preoperative assessment, invasive EEGs are used to clarify: 1) whether a seizure patient is a viable candidate for resective surgery, 2) where the seizures originate (therefore, where to resect) and 3) how much to resect. METHODS: We retrospectively collected data for 88 patients, focusing on those who underwent surgery and received a seizure outcome. RESULTS: Of n=88 patients, 51/88 were female with a mean age of 31.9 years. 84/88 patients had at least one-year follow-up after surgery and 19/84 had no resective surgery. Of the remaining 65 patients, 36 had strips alone and 25 had both strips & grids implanted. 29/65 had multi-lobe implants while 46.2% (30/65) had implants solely in the temporal lobe. The most common electrode arrangements were bitemporal (29/65), unilateral multi-lobar (20/65), and unilateral multi-lobar (6/65). All n=65 patients received an Engel Classification (I=23/65, II=21/65, III=15/65, IV= 6/65). After statistics were applied, strips/grid designs were found to be unrelated to outcome (p-value \u3e.05). CONCLUSION: Electrode arrangement did not predict a favorable outcome (Class I). Other factors such as compliance with medical management and seizure characteristics must be considered if a predictor for optimal post-operative outcome is to be found